Table 1.
Sensitivity and specificity for each virus detected with the Fluorecare® combo antigenic test across various RT-qPCR Ct value ranges. .
| No. of positive patients with RAD test (Sensitivity%) (Pos. / total) | ||||
|---|---|---|---|---|
| Ct (gene N) | Influenza A | Influenza B | SARS-CoV-2 | RSV |
| < 20 | 12/12 (100%) | 12/12 (100%) | 13/15 (86.7%) | 13/17 (76.5%) |
| < 25 | 28/29 (96.5%) | 29/31 (93.5%) | 27/31 (87.1%) | 16/26 (61.5%) |
| < 30 | 37/42 (88.1%) | 30/41 (73.2%) | 31/38 (81.6%) | 17/36 (47.2%) |
| 20 – 25 | 16/17 (94.1%) | 17/19 (89.5%) | 14/16 (87.5%) | 3/9 (33.3%) |
| 25 – 30 | 8/13 (61.5%) | 1/10 (10.0%) | 4/7 (57.1%) | 1/10 (10%) |
| 30 – 35 | 6/10 (60%) | 1/6 (16.6%) | 4/7 (57.1%) | 0/5 (0%) |
|
Total (< 35) [95%CI] |
42/52 (80.8%) [67.2 – 94.4] |
31/47 (65.9%) [51.6 – 80.2] |
35/45 (77.8%) [63.2 – 92.4] |
17/41 (41.5%) [26.2 – 56.8] |
|
Mean Ct [95%CI] |
24.26 [22.68 – 25.84] |
23.40 [21.87–24.93] |
22.58 [20.91–24.24] |
22.88 [21.28–24.48] |
|
No. Of Negative Patients with RAD test (Specificity%) (Neg. / total) | ||||
| Neg. with RT-qPCR [95%CI] |
121/126 (96.0%) [87.3 – 100] |
127/131 (96.9%) [88.33 – 100] |
133/133 (100%) [91.5 – 100] |
135/135 (100%) [91.6 – 100] |
Abbreviations: CI, Confidence Interval; Ct, cycle thresholds; RAD, Rapid Antigen Diagnostic; RSV, Respiratory Syncytial Virus; RT-qPCR, Reverse Transcriptase quantitative Polymerase Chain Reaction.